The "deChannel" channel header contains the following information on the extracted channels. One row is assigned to each channel.
_FileID
Unique internal ID assigned to each dataset
_ChannelNr
Unique internal channel ID assigned to the extracted signal
_Name
Name of the extracted signal
_Unit
Physical unit of the extracted signal
_IsDigital
This flag is set when the signal is "logical".
_Interval
Storage interval of the extracted data, see Archive profile assignment
_IsTimeInterval
This flag is set for timebased datasets.
_Segments
This column contains compressed data, which is extracted as BLOBs (binary large objects) if the corresponding option is selected for extraction, see Using BLOBs.
The "deChannel" is displayed in the database as shown in the following figures.
Without BLOBs:

With BLOBs:

For vector signals, the _LogicalID column is created additionally.